Ignition apparatus for internal-combustion engines



Sept. 1l, 1928. 1,684,343

M. M. cARDELLlNo IGNITION APPARATUS FOR INTERNAL COMBUSTION ENGINES Filed June 28, 1927 2 Sheets-Sheet l Fig. 2

mmm

sept 11, 192s.

M. M. CARDELLINO IGNITION APPARATUS FOR INTERNAL COMBUSTION ENGINES Filed June 28, 1927 2V Sheets-Sheet 2 Fig. 10

flllllllllllllllllllllllllllllll Patented Sept. 11, 1928.

UNITED STATES PATENT OFFICE.

HIGELO HABIA CABDELLINO, F TURIN, ITALY.

IGNITION APPARATUS FOR mERNAL-OOMBUSTION ENGmE.

pplioatlon led Iunei28, 1927, Serial No. 202,029, and in Great Britain Iuly 81, 1928.

This invention relates to ignition magnetos o the kind having tubular magnets with pole pieces, in which new arrangements are provided in the construction of the rotor, of the pole shoes andin the winding, so that the apparatus can generate directly high tension currents without the Ause of contact breaker,

condenser and transformer. The magneto is constructed to produany desired number of sparks per revolution, that is, normally as many as the number of the engine cylinders; it has, therefore, no gear for operating the distributor, which is reduced to its simplest construction and forms one member with the rotor. v

The annexed drawings illustrate the in. vention and show, by way lof example, a constructional form of the apparatus producing eight sparks per revolution.

Figures 1 and 2J are diagrams of the magnetic circuits in the first working posltlon;

Figures 3 and 4 are similar diagrams showixg the rmagnetic circuits after a rotation o 450 Figlires 5 .and 6 are diagrams, similar to thoseof Figure 1, of two-modified forms;

Figure 7 shows a section of a constructional` form of the apparatus the section being through the line VII-VII of Figure 8. the

latter being a section on the line VIII-VIII of Figure 7 Figure 9 is a section on line IX--IX of Figure 8;

Figure 10 is a perspective view of the rotor.

With reference to the drawings, 1 denotes the tubular magnet of the apparatuscarrying at its oppositely vmagnetlzed ends lannnated pole shoes 2,2. Two supportlng caps 3 secured at thei) two ends fo thgedtublultar m et su ort means o an p a es 4 iird 5 allminatycd pore 6 on the ends of which are mounted two starshaped laminated pole shoes 7, 7 having-"a number'of teeth corresponding to that of the pole shoes 2. s

The pole shoes 7 are embedded in an insulator 8 supporting laminated bars 9, the number of which is equal to the numberofthe teeth of the pole shoes 2 and 7 and' each isarranged, between two teeth of the` latter, around the core 6, thus forming a cylindrical cage. On the core 6 is wound avcoil 10 having a large number of turns (in the case now considered 60,000 turnsof 6 /100 mm. are

used) and occupying all the ace com rised between the core `6 and the bzsas 9. P

The space between the bars above the coil is conveniently filled with an insulating material so that the rotor has the appearance of a perfectly smooth cylinder.

One 'of the coil ends is grounded while the other end is connected with two electrodes 11 embedded in the insulating material and arranged at 180 'to each other and rotating in two parallel planes in each of-which are arranged four electric connections comprising an insulator 13 and a central electrode 14 projecting in such a manner that the rotating electrode 11 passes in close proximity thereto without touching it.

The apparatus works as follows AIn the position shown in Figures 1 and 2 the magnetic circuit is formed by a tubular magnet 1, pole shoes 2, pole shoe 7, core 6. pole shoe 7', pole shoe 2', magnet 1 so that all the flux passes centrally through the coil.

When the rotor is displaced by 45. from the described position in Figures 1 and 2, arriving in the position shown in Figures 3 and 4, the teeth of the pole shoes 7 are no longer in front of the teeth of the pole shoes 2. and their place is occupied by the bar 9 thrqugh'which the magnetic circuit is closed cuttlng out the pole shoes 7, 7 and the core 6. The flux flows thus entirely outside the coil 10 so that a variation of induction in the coil,

is produced as the flux maintains the same direction with regard to the magnet. This operation takesplace eight times each revolution therefore eight successive high tension impulses and consequently eight sparks will be produced.

The position of the electrodes 11 is such that when an impulse is produced, an electrode 11 will be opposite to an electrode 14 so that the high tension current is brought to the corresponding spark plug.

Each electrode 11 will successively feed the four corresponding electric connections during a half revolution and during the further 180 it works as -a direct conductor between the 'coil 10 and magnet 1 while the secyond electrode feeds the other four electric' connections.

If the magneto has to give a number of sparksother than eight each revolution, it will be suicient to vary the number of teeth of the pole shoes 2 and 7 and bars 9: said number must always be equal to one half the number of sparks to be produced at each revolution.

The number of the electric connections must, of course, correspond to the number of sparks to be produced at each revolution and their arrangement may vary according to requirements and design.A i

Thus, for instance, in a magneto producing twelve sparks at each revolutlon the simplest arrangement would be placing all the electric connections radially `in a single plane and feeding t-hem throu h a'single elect-rode 4l1 but it Will generally e preferred to place the electric connections in two rows each lof six connections and feeding them through two electrodes placed at 180 or still better in three rows each of four connections fed by three electrodes placed at 120 to each other.

What I claim is:

1. A multi-polar ignition magneto for internal combustion engines' comprising a rotor having a laminated iron core, a single Winding on the core formin a coil, laminated pole shoes on the ends of t e core having a number of teeth equal to half the number of sparks to be produced at each revolution, and laminated bars of the same length as the rotor arranged between each two teeth and constituting a cylindrical cage for the coil whereby the flux alternately closes within and without the coil, always in the same direction through the magnet. y

2. A multi-polar ignition magneto for internal combustion engines, comp-rising a tubular magnet provided with laminated pole shoes without windings, a rotor having a laminated core arranged in the magnet, a

'single winding on the core forming a coil,

laminated pole shoes on the ends of the core having a number of teeth equal to half the number of sparks to be produced at each revolution, and laminatedbars of the same lengt-h as the rotor arranged between each two teeth and constituting a cylindrical cage for the coil whereby the flux alternately closes within and. without the coil, always in the same direction through the magnet.

In testimony that I claimthe foregoingv as my invention, I have signed my name.

MICHELANGELO MARIA CARDELLINO. 

